A Novel Approach to Cyclic Polysulfides via the Controlled Ring-Expansion Polymerization of Cyclic Thiourethane with Thiiranes
A Novel Approach to Cyclic Polysulfides via the Controlled Ring-Expansion Polymerization of Cyclic Thiourethane with Thiiranes
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DOI：
10.1021/ma7026287
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发表时间：
2008-01
期刊：
影响因子：
5.5
通讯作者：
Hiroto Kudo;Masa-aki Sato;R. Wakai;T. Iwamoto;T. Nishikubo
中科院分区：
文献类型：
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作者：
Hiroto Kudo;Masa-aki Sato;R. Wakai;T. Iwamoto;T. Nishikubo
合成结构明确的环状聚合物的方法的发展对高分子化学的发展具有重要的意义。合成环状聚合物有两种众所周知的策略。一个是末端含有两个活性基团的线性化合物的闭环反应1，另一个是环状化合物的扩环聚合2。前一种方法通常需要高度稀释的条件，并且难以以令人满意的产率获得环状聚合物，因为线性聚合物也可以同时形成。后一种方法的优点在于，通过调节单体进料比可以高产率合成较高分子量的环状聚合物，但是在这种情况下，不容易控制分子量，并且所得环状聚合物的多分散性比率通常随着其分子量的增加而增加。在以前的报道中，我们提出了一种使用季盐作为催化剂合成环状聚合物的环状硫酯的扩环聚合。分子内和分子间的反应进行之间的硫酯部分，得到各种大小的大环。本文通过环硫乙烷与环硫氨酯的连续插入反应，成功地合成了分子量可控的新型环状聚合物。以四丁基溴化铵（TBAB）为催化剂，考察了苯氧基丙基硫醚（PPS）和苯硫代氨基甲酸苯酯（PBT）的不同投料摩尔比下，在NMP中24 h的硫杂环丙烷连续插入线型硫代氨基甲酸酯的反应在进料中PBT/PPS为1/50的情况下，得到相应的聚硫化物PBT-1-聚（PPS）50，其数均分子量（Mn）为6100，多分散性比（Mw/Mn）为1.17.通过1H NMR和IR光谱证实了PBT-1-poly（PPS）50的结构。4基于PPS插入反应产生的10.42 ppm处的-NH-质子和-CH 2 O-部分的亚甲基质子的信号，计算PPS向硫代氨基甲酸酯部分中的连续插入反应（DI）的程度
The development of synthetic process for well-defined cyclic polymers has more attractive attention for advancement of polymer chemistry. There are two well-known strategies for synthesizing cyclic polymers. One is the ring-closure reaction1 of linear compounds containing two reactive groups at the ends, and the other is the ring-expansion polymerization2 of cyclic compounds. The former approach generally requires highly diluted conditions, and it is difficult to obtain the cyclic polymers in satisfactory yields, because linear polymers can be also formed at the same time. The latter approach has the advantage that the higher molecular weights cyclic polymers can be synthesized in high yields by adjustment of the monomer feed ratio, but in this case, it is not easy to control the molecular weights and the polydispersity ratios of the resulting cyclic polymers often increase with increasing their molecular weights. In previous reports, we3 presented a ring-expansion polymerization of cyclic thioesters using quaternary onium salts as catalysts for the synthesis of cyclic polymers. Both intra-and intermolecular reactions proceeded between the thioester moieties to give various sizes of macrocycles. In this paper, we succeeded the synthesis of new cyclic polymers with controlled molecular weight by the continuous insertion reaction of thiirane into cyclic thiourethane. As the references, the continuous insertion reaction of thiirane into linear thiourethane was examined in the presence of tetrabutylammonium bromide (TBAB) as a catalyst in NMP for 24 h with the various feed molar ratios of phenoxypropyrenesulfide (PPS) and phenyl benzenethiocarbamate (PBT)(Scheme 1A).In the case of feed of PBT/PPS) 1/50 in the feed, the corresponding polysulfide PBT-l-poly (PPS) 50 was obtained with number-average molecular weights (Mn)) 6100 and polydispersity ratio (Mw/Mn)) 1.17. The structure of PBT-l-poly-(PPS) 50 was confirmed by the 1H NMR and IR spectroscopy. 4 The extent of the continuous insertion reaction (DI) of PPS into the thiourethane moiety was calculated based on the signals of the-NH-protons at 10.42 ppm and methylene protons of-CH2O-moieties produced by the insertion reaction of PPS